Tools for inserting arbors in watch main springs



Oct. 8, 1963 E. J. RENZ 3,106,115

TOOLS FOR INSERTING ARBORS IN WATCH MAIN SPRINGS Filed July 6, 1962INVENTOR E James Renz United States Patent This invention relates tomeans by which watch main springs can be readily and convenientlyprovided with a barrel arbor, and it consists of a device by which thecentral or inner convolution or loop of the main spring will be elevatedand distended whereby the arbor can be easily fitted within the springand engaged therewith. It is an object of the invention to provide adevice of 7 this character arranged for the accommodation of springs ofvarious sizes; which will accept springs provided with an encirclingring, and which will greatly facilitate the insertion of an arbor withinthe spring.

More particularly, the invention contemplates the provision of -a plateor block that is provided in its upper surface with a plurality ofspaced circular recesses of different diameters for the reception ofmain springs of different sizes. Centrally located on the base of eachof the recesses is a conical, upstanding projection provided with acentral hole or closed bottom deep recess. In operation, one of the mainsprings provided with an encircling annulus or disk is placed in therecess of required size, and the central convolution or loop of thespring, so positioned, will fit over the projection at the bottom of therecess, thereby causing the loop of the spring to be both slightlyelevated and distended. In such elevated and distended position of theloop, the central part of the spring is made accessible to enable anarbor to be readily inserted within the loop and pressed down to engagethe loop while one of the shaft portions of the arbor enters into thehole provided through the conical projection.

With these and other objects to be hereinafter set forth in view, I havedevised the arrangement of parts to be described and more particularlypointed out in the claims appended hereto.

In the accompanying drawing, wherein an illustrative embodiment of theinvention is disclosed,

FIG. 1 is a top plan view of a tool constructed according to the presentinvention;

FIG. 2 is an enlarged view of a part of the tool, showing one of thespring-receiving recesses therein;

FIG. 3 is a sectional view, taken substantially on the line 33 of FIG.2, looking in the direction of the arrows;

FIG. 4 is a vertical sectional view through a part of the tool showinghow the same receives a main spring and wound strip confined in itswound condition by means of "ice 2 aperture, not shown, for engagementby a tooth 4 provided on the central barrel portion 5 of an arbor 12which is adapted for insertion within the loop or inner convolutions 5of the spring.

The encircling collar or ring 2 is in the form of an annular disk and itmay be composed of metal or plastic and it serves to surround and holdthe spring 1 in its coiled condition substantially as shown in FIGS. 5and 6 and it is supplied to the watch-maker in such condition by themanufacturer.

The improved tool consists of a flat plate or block 6 provided in itsupper surface with a plurality of circular, relatively shallow recessesor depressions 7, the same being graduated in size for the accommodationof main springs of various sizes. The plate or block 6 may be made invarious sizes and the number of recesses employed in it may be increasedor decreased to meet requirements.

Extending centrally and upwardly from the base surf-ace 8 of each of therecesses 7 is a conical projection or elevation 9 formed with a centralhole or deep closed-bottom recess 1%, said hole or recess being adaptedfor the reception of the shaft portion 11 of the arbor 12 when the arboris fitted within the central convolution or loop 3 of the main spring.

Each of the conical projections 9 is relatively small compared to theoverall size of each recess 10 in which the projection is located sothat an annular spacing is provided between the conical projection andthe side wall of the recess to thereby accommodate all the convolutionsof the spring and the encircling collar 2, the central convolution 3'being the only convolution engaged by the projection 9.

In the use of the tool, the watchrnalrer selects a recess 7 of therequired size and the spring 1, provided with the encircling collar 2are placed in the recess substantially as shown in FIG. 4, bringing thecentral convolution or loop 3 of the spring over the raisedconicalprojection 9 on the bottom surface of the recess. As the springis pressed downwardly, the tapered shape of the conical projection willtend to raise the loop 3 slightly and at the same time it will expand orspread the same.

The arbor 12, which may be held in a suit-able tool, is now insertedwithin the loop or convolution 3 to bring its part 5 therein and whenturned slightly it will force the loop portion 3 down against theconical projection and expand it further so that the arbor can easilyenter the loop and the tooth 4 on the arbor caused to engage the recessin the loop 3-. As the arbor is forced into position as above described,its shaft portion 11 will enter the hole or recess 10 and will thus beprevented from being damaged during the attachment of the arbor to themain spring.

The provision of a plurality of differently-sized recesses 7 in the baseblock or plate 6 provides the Watchmaker with a universal tool usefulfor main springs of many different sizes and the provision of thesprings with a fiat encircling collar enables the springs to be easilyhandled and fitted into and removed trorn the recesses 7 in the blockafter the application of the arbor.

Having thus described a single embodiment of the invention, it isobvious that the same is not to be restricted thereto, but is broadenough to cover all structures coming Within the scope of the annexedclaim.

What I claim is:

A tool for fitting an arbor in a Watch main spring in 3 which the springhas an encircling member consisting of a disk-shaped annulus, theimprovement consisting in a block having a circular recess formed in it,said recess having a central, conical, raised projection for engagingonly the inner loop on the spring when the spring and its encirclingmember are inserted Within the recess, the recess having a relativelywide annular spacing between the base of the conical projection and theside wall of the recess t0 therein accommodate the convolutio ns of thespring other than the inner loop thereof which is engaged by theprojection, the projectionhaving a central recess for receiving theshaft of an arbor when the arbor is fitted within the central loop ofthe spring.

References Cited in the file of this patent UNITED STATES PATENTS484,680 Smith Oct. 18, 1892 1,069,539 Evans Aug. 5, 1913 2,634,636Wilson Apr. 14, 1953 FOREIGN PATENTS 117,811 Switzerland Dec. 1, 1926

